Section R. 325.10611f - Enhanced treatment for Cryptosporidium; treatment technique; additional Cryptosporidium treatment requirementsRule 611f.
(1) Subpart H supplies are also considered "water supplies" or "supplies" in this rule. Subpart H supplies that are subject to R 325.10611d shall provide the level of additional treatment for Cryptosporidium specified in the following table based on their bin classification as determined under R 325.10611e and according to the schedule in R 325.10611g: | If the supply bin classification is ... | And the supply uses the following filtration treatment in full compliance with R 325.10611 to R 325.10611c, R 325.10720 to R 325.10720a, and R 325.10722, as applicable, then the additional Cryptosporidium treatment requirements are ... |
| Conventional filtration or membrane filtration treatment (including softening) | Direct filtration | Slow sand or diatomaceous earth filtration | Alternative filtration technologies approved by the department under R 325.10611b (3) |
| Bin 1 | No additional treatment | No additional treatment | No additional treatment | No additional treatment |
| Bin 2 | 1-log treatment | 1.5-log treatment | 1-log treatment | Note 1 |
| Bin 3 | 2-log treatment | 2.5-log treatment | 2-log treatment | Note 2 |
| Bin 4 | 2.5-log treatment | 3-log treatment | 2.5-log treatment | Note 3 |
Note 1: As determined by the department such that the total Cryptosporidium removal and inactivation is not less than 4.0-log.
Note 2: As determined by the department such that the total Cryptosporidium removal and inactivation is not less than 5.0-log.
Note 3: As determined by the department such that the total Cryptosporidium removal and inactivation is not less than 5.5-log.
(2) All of the following provisions apply to microbial toolbox options: (a) Supplies shall use 1 or more of the treatment and management options listed in R 325.10611h, termed the microbial toolbox, to comply with the additional Cryptosporidium treatment required in subrule (1) of this rule.(b) Supplies classified in Bin 3 and Bin 4 shall achieve not less than 1-log of the additional Cryptosporidium treatment required under subrule (1) of this rule using either 1 or a combination of the following: bag filters, bank filtration, cartridge filters, chlorine dioxide, membranes, ozone, or UV, as described in R 325.10611i to R 325.10611m.(3) Failure by a supply in any month to achieve treatment credit by meeting criteria in R 325.10611i to R 325.10611m for microbial toolbox options that is not less than equal to the level of treatment required in subrule (1) of this rule is a violation of the treatment technique requirement.(4) If the department determines during a sanitary survey or an equivalent source water assessment that after a supply completed the monitoring conducted under 40 CFR §141.701 (a) or 40 CFR §141.701 (b), as adopted by reference in R 325.10720b, significant changes occurred in the supply's watershed that could lead to increased contamination of the source water by Cryptosporidium, the supply shall take actions specified by the department to address the contamination. These actions may include additional source water monitoring or implementing microbial toolbox options listed in R 325.10611h, or both.Mich. Admin. Code R. 325.10611f